The invention pertains to an apparatus for automatically removing machining burrs from a previously machined article.
Machining of metal parts by cutting tools such as milling cutters, machine drills, boring tools and the like, produces burrs at the edges of the cut where the cutting tool enters and leaves the surface of the metal. Removal of the burrs has caused a great deal of problems, particularly in automated metal working transfer machines in which a variety of machining operations are performed on the metal part at a number of different work stations. Because of tolerance build up and inaccuracies in the various cutting operations carried out on such a machine, there is considerable variation between the actual and nominal, or design, location of a given cut, such as a groove or slot in the surface of the part. For that reason the precise position of the edge to be deburred can not be predicted with sufficient accuracy for the burrs to be removed by conventional automated metal working machines without damage to the adjacent surfaces. Various other methods for removing the burrs have been tried without much success. An attempt has been made, for example, to remove the burrs by means of electrolytic machinery in which the electrode was used to burn out or unplate the burr from the machined part. Because of the cost of the electrodes and the short life of the equipment, this method, however, was found to be too costly to be practical. A number of other deburring methods, such as heating to high temperatures by electrical discharge, chemical treatment, shot blasting and the like, have also been tried with equal lack of success. Since none of these methods proved to be practical or economical, the deburring operation has theretofore usually been performed manually.
Removal of burrs by hand in mass production of machine parts is, however, a very slow and expensive operation markedly increasing the cost of the product. Deburring, for example, is a serious problem and a major factor in the cost of fabricating diesel piston connecting rods. In the production of the connecting rods, all the machining operations are carried out on a single transfer machine having a number of work stations for cutting the lubricating channels and keeper slots in the wall of the journal bore, boring the journal and performing various other machining operations on the connecting rod as it is transferred from station to station. As the oil grooves and keeper slots are cut in the sides of the bore, in such a machining operation, burrs form at the edges and are pushed into the cuts during the subsequent boring of the journal. Since the burrs, if left in place, would interfere with the flow of the lubricating oil and the proper seating of the journal bearing, they must be removed at the end of the machining operation. The cost of removing the burrs, a process which is carried out by hand, is amply illustrated by the fact that although the transfer machine can be run by two or three operators, the manual removal of the burrs requires as many as twenty operators to keep up with the machine.
The object of this invention is to provide an automatic deburring machine capable of rapidly removing machining burrs from slots, grooves or other cuts in the surface of a work piece even though the cuts may deviate considerably from their nominal locations.